Musicians, take note: An artistic mind isn’t required to create appealing music. Starting with short sound sequences more grating than Muzak, scientists created pleasing tunes simply by letting them evolve through a Pandora-like process of voting thumbs up or thumbs down on each sequence.

Inspired in part by long-running experiments probing the evolution of bacteria, computational biologist Bob MacCallum and colleagues decided to see if pleasant music could evolve from a cacophonous mess w...